摘要
在天然气储层识别和生产能力评价中,存在两个矛盾:一是应用挖掘效应进行气层判断时误差较大;二是根据孔隙度、空隙空间结构、渗透率、饱和度、有效厚度等参数来确定生产能力时,其参数值越大并不表明产能越高。为此提出了天然气充盈度的概念,在分析充盈度及天然气密度的决定因素基础上,利用常规测井资料的含氢指数和经骨架密度校正的密度孔隙度及其相应图版,计算地层孔隙度及冲刷带含水饱和度,然后再根据密度体积方程计算地下天然气密度,最后计算出地层压力和充盈度参数。根据所计算出的充盈度结果,不仅搞清了产生上述矛盾的机理,而且还发现充盈度与产能有着良好的正相关性,从而提高了天然气储层评价的准确度,有助于科学预测气藏的分布和富集程度。
Two problems exist in gas reservoir identification and productivity estimation.One is that a big error occurs when gas layers are identified according to the excavation effect.The other is that gas productivity can not be really determined by those parameters such as porosity,pore structure,permeability,saturation and net thickness,the higher values of which do not mean a higher productivity.A new concept of gas suffusive degree is presented to solve these problems.Based on analysis of the determinative factors of gas suffusive degree and density,the hydrogen index from conventional logging data and the matrix-density-corrected density porosity and its associated chart board are used to calculate the in-situ porosity and the water saturation of wash zones.Then,in-situ gas density is calculated by using density-volume equation.Finally,formation pressure and gas suffusive degree are calculated.The calculation of suffusive degree reveals not only the causes of the above-mentioned two problems but also the positive correlation between suffusive degree and productivity.This parameter can enhance the accuracy of gas reservoir appraisal and help predict gas distribution and the level of enrichment.
出处
《天然气工业》
EI
CAS
CSCD
北大核心
2010年第6期31-34,共4页
Natural Gas Industry
关键词
充盈度
天然气
储集层
生产能力
密度
数学模型
评价
suffusive degree,natural gas,reservoir,productivity,density,mathematical model,appraisal
